Neutral grounding resistors (NGR), also known as neutral earthing resistors, fulfill a crucial function in terms of safety. In the event of earth fault in electric networks, they protect power transformers, generators and other pieces of electric equipment from damages. In direct grounding, the resistance would be limited to that of the soil. But inserting this kind of resistors between the neutral and the ground increases the net resistance and allows to keep the current at safe levels in case of earth fault. The benefits of NGR consists in:

  • Securing electrical equipment in high-voltage and medium-voltage electrical networks,
  • Reducing maintenance and operational costs,
  • Increase the overall safety of the implant in which they are installed


Whenever direct grounding is not enough, NGRs are called for. This is the case for virtually every electric networks for which failure is not an option. For instance:

  • Hospitals
  • Industrial and power plants
  • Mining sites


Fairfild’s develops many custom of those resistors, based on the specific needs of the client. But Fairfild also has in stock a wide array of resistors that can serve the purpose of neutral grounding. Among their characteristics:

  • Power ratings from 15 W up to 3.5 kW
  • Non-sealed and sealed resistors for extreme weather conditions
  • Non-filled and filled resistors for superior thermal capacity